This is an interesting product. Looks to me like it integrates your smartphone with a walkie-talkie radio signal to communicate with other "goTenna" connected devices.

I recall a cell phone some years back that had a built-in GMRS radio but what makes this different is that this creates a network of devices where each device will extend the range of the network to include it's own reach, and it only sends text messages, it does not do voice communications.

This would be pretty handy for backpackers hiking popular trails like the AT. For example, this device could help in situation like the one where the woman got lost after meandering off trail on the AT a few years ago.

It's also touted as a viable option for emergency and disaster event communications. It wouldn't surprise me if this concept is integrated into smart phones soon (within a decade anyway).